Twenty man were tested in step-input tracking. Minor stress was imposed by moderate alcohol dosage and an incompatible directional relation between control and display. Some target movements demanded a response an improbable direction and posed a choice between long delay in response and a movement in a wrong direction. The duration of response latency (rl) and the number of directional errors revealed a S's preference for accuracy or speed and his ability to estimate probabilities. Directional-errors, response latencies, and eye movements were recorded before and after drinking, when breathanalyzer (ba) readings were zero, and at 0.05 percent and 0.1 percent ba levels, which may be produced in a man weighting 160 lbsby drinking two and four 12 oz bottles of beer, respectively. Alcohol caused a progressive increase in rls and errors (p <0.01); there was no evidence for a threshold below which alcohol has no adverse effect. The test emphasized the markedly different effects of the same alcohol dosage on the skill of different Ss, but habitual drinkers obtained no undue advantage on the test. The task was learned quickly and extensive practice did not reduce the discriminatory power of the test. The effects of a dose producing a 0.05 percent ba reading were significantly different in an ascending or descending series of levels of intoxication. The alcohol dosages tested had no significant effect on simple reaction time.
Abstract